JP2019514199A - Method and apparatus for bonding two substrates - Google Patents

Abstract

The present invention relates to a method and apparatus for bonding two substrates.

Description

  The application of the present invention describes a method and apparatus for bonding two substrates.

  In particular, the product wafer needs to be stabilized by the carrier wafer for back thinning of the product wafer scheduled in the production process. After backside thinning, the product wafer reaches a thickness of less than 100 μm, usually less than 50 μm, already about 20 μm today, and probably 1 μm to 20 μm in the near future. The wafer can be extremely thinned for stabilization by the carrier wafer, and after back thinning further processing steps with standardized processes can be carried out.

  In the semiconductor industry, product wafers are temporarily attached to carrier wafers increasingly frequently. The adhesive, so-called bonding adhesive, is in this case applied in the form of a layer having a layer thickness which is as uniform as possible on the product wafer and / or the carrier wafer. After the coating process, both wafers must of course be pressed together with a strong force. This process is known under the concept of bonding.

  A widespread method for securing a wafer to a glass carrier is to affix the glass carrier to the substrate in a large area. In this case, the adhesive used has the property that it loses its adhesive properties when the predetermined temperature is exceeded. Thus, for the separation of the wafer and the glass carrier, energy is introduced through the glass carrier, for example thermally or with a laser, by means of which energy the adhesive loses its adhesive properties. Loss of adhesion properties is also usually accompanied by a reduction in viscosity. Thereafter, the substrate and the glass carrier can be separated from one another.

When using a thermoplastic resin having a low glass transition temperature T _g as a bonding adhesive in the temporary bonding, peeling occurs in the wafer edge by the high temperature and / or stress of the product wafer during various back process Sometimes. Polyimides with low T _g (eg, about 40 ° C.) are temperature stable, but at elevated temperatures the bonding adhesive has very low cohesion, or the bonding adhesive has a lower viscosity as it flows out of the interface.

For example, a thermoplastic resin having a high T _g, such as polyimide HD-3007 has the disadvantage that cleaning is extremely difficult and a strong solvent is not especially could attack the passivation of the product wafer.

  When crosslinkable materials are used as bonding adhesives, it is often very difficult to debond, especially when high structure or undesirable surface material is present on the product wafer. Here, debonding or cleaning is laborious and often requires strong chemicals.

  In the case of the known method, it is a disadvantage especially that the adhesive is destroyed already by the temperature generated during the back-end processing process, whereby the wafer has already peeled off from its carrier during this process. In this case, premature release of the adhesive can lead to destruction of the substrate, ie the product wafer.

  Another known method works with sheets provided with an adhesive layer. This adhesive also loses its adhesive properties when the predetermined temperature is exceeded. As in the case of the above-described method, the high temperatures already generated during the back-end processing can lead to a break in the bond between the carrier substrate and the product substrate.

  Often, multiple layers are created between the product substrate and the carrier substrate to achieve improved debonding. In WO 2010/121068 (WO 2010/121068 A2), for example, a UV-curable adhesive layer and a laser-softenable separation layer are combined. Laser irradiation changes the chemical-physical properties of the separation layer. Debonding between the product substrate and the carrier substrate is performed by this separation layer. However, multilayer systems are relatively laborious to manufacture.

  Thus, the object of the invention is, on the one hand, to produce a high bond strength between the substrates, produced with minimal effort for all necessary process steps, and on the other hand, to process thin product substrates after processing of the substrate bonding. It is an object of the present invention to provide an apparatus and a method for enabling separation from the substrate complex without destruction. Furthermore, the method steps necessary for this process should be possible at low cost and for a wide variety of substrates.

  This task is solved by the subject matter of the independent claims. Preferred developments of the invention are described in the dependent claims. All combinations of at least two of the features described in the description, the claims and / or the drawings are also within the scope of the present invention. For the stated value ranges, values which fall within the stated boundaries are also disclosed as limit values and should be able to be claimed in any combination.

The present invention has the following steps:
a) applying a bonding adhesive on the product substrate and / or the carrier substrate to form a bonding adhesive layer,
b) bonding the carrier substrate to the product substrate via a bonding adhesive layer,
c) temporarily bonding the product substrate with the carrier substrate, curing only a partial region of the bonding adhesive layer and not curing or at least essentially curing the remaining regions of the bonding adhesive layer On the way.

The invention further provides:
a) coating means for applying a bonding adhesive on the product substrate and / or the carrier substrate to form a bonding adhesive layer;
b) bonding means for bonding the carrier substrate to the product substrate via the bonding adhesive layer;
c) temporarily curing the product substrate with the carrier substrate, with a curing device which cures only a partial area of the bonding adhesive layer and which does not or at least essentially does not cure the remaining areas of the bonding adhesive layer It relates to an apparatus for joining.

The method according to the invention or the device according to the invention in particular has the following advantages:
1. There is a protective layer between the product substrate and the carrier substrate,
2. Regional control of the curing of the bonding adhesive layer is possible.
3. No additional anti-adhesion coating is required. The adhesion does not have to be reduced by the adhesion reduction layer. Thereby, fewer process steps occur, or the product substrate and / or the carrier substrate do not have to be pretreated.

  Bonding adhesive layers include adhesives, such as peelable adhesives, in particular thermoplastic resins.

  Curing may be performed by electromagnetic radiation, heat, current, magnetic fields, and / or other methods.

  Preferably, the bonding adhesive is applied to the entire surface of the product substrate and / or the carrier substrate. Thereby, the manufacturing process is extremely simplified, which can increase the throughput. Furthermore, the bonding adhesive layer acts as a fill layer to protect the structure and to easily peel the carrier substrate and the product substrate.

  Alternatively, the bonding adhesive is preferably applied annularly to partial areas on the product substrate and / or the carrier substrate, in particular to the outer edge of the product substrate and / or the carrier substrate. Thereby, peeling can preferably be simplified.

  If a bonding adhesive is applied to the partial area, in particular the circular inner area is left uncovered. Debonding (debonding) takes place in particular in the annular area between the carrier substrate and the product wafer. The areas to be cured can be preset by means of a mask. In this case, in particular only the exposed outer area of the bonding adhesive is crosslinked. The inner area remains unexposed so that little polymerization takes place in this area. The bonding layer consists of two differently cross-linked areas, the polymerized annular outer area being used for temporary bonding.

  Preferably, the bonding adhesive is applied on the structure of the product substrate. Thereby, protection of the structure can preferably be achieved.

  Preferably, the curing of the partial area is carried out by irradiation, preferably by UV radiation, in which case the curing device can comprise one, in particular a single radiation source, and / or an array of light sources. In particular, a mask is arranged between the radiation source and the substrate in order to shield the remaining area. The mask preferably comprises areas which are transparent to the radiation of the radiation source and areas which are opaque to it. Alternatively, the curing of the partial area is performed by irradiation with light sources aligned with one another, in particular a light source array with UV light sources, which can in particular be controlled individually.

  Preferably, only the outermost edge area of the bonding adhesive layer is cured. This facilitates the exfoliation of the substrates from one another.

  Preferably, the remaining area inside the bonding adhesive layer is not cured or at least essentially not cured. As the structure of the product substrate can be present here, an improvement of the protection of the structure can be achieved.

  At least one of the two substrates, in particular the carrier substrate, can be transparent to electromagnetic radiation in the wavelength range which causes crosslinking of the bonding adhesive.

  In the case of the present invention, only the partial area to be cured of the bonding adhesive is treated. This is preferably a peripheral area. The remaining, in particular the central part, is not treated and is therefore not or only slightly crosslinked. This makes it possible to use a homogeneous, in particular an entire, preferably a single bonding layer, which exhibits its adhesive properties, in particular by curing at the edges, and the bonding layer In particular for the protection of the structure and for easier peeling of the carrier substrate and the product substrate, in particular in the inner region it plays the role of a filling layer.

Preferably, a material having a high glass transition temperature (T _g ) can also be used, since this material preferably solidifies only at the periphery and only upon crosslinking. Bonding and debonding is possible at about room temperature.

  Substrates are understood to be product substrates or carrier substrates used in the semiconductor industry. The substrate is preferably a wafer or a product wafer. The substrate may have any arbitrary shape but is preferably circular. The diameter of the substrate is standardized, in particular industrially. The wafers are of industrially conventional diameter: 1 inch, 2 inches, 3 inches, 4 inches, 5 inches, 6 inches, 8 inches, 12 inches and 18 inches. However, the preferred embodiments of the present invention are capable of processing essentially each substrate independently of its diameter. The product substrate may be a product substrate that is structured or processed on both sides.

  In the ideal case, the layers for the bonding procedure according to the invention have a uniform thickness. Uniform thickness in this context means that the thickness of the bonding layer is the same at each position or within an acceptable tolerance.

As adhesives or bonding adhesives, both thermoplastic resins with low glass transition temperatures (T _g ), thermoplastic resins with high glass transition temperatures and crosslinked polymers are used. Glass transition temperature is the temperature range over which plastics are exposed to large changes in deformability. Factors such as, for example, molecular weight, degree of crosslinking, end groups, plasticizers, degree of crystallinity, and intermolecular forces affect the glass transition temperature.

  Plastics, depending on their properties, can be divided into four main groups: elastomers, thermoplastic elastomers, thermoplastic resins and thermosetting resins. The elastomer (weakly crosslinked), the thermoplastic elastomer (crosslinked) and the thermosetting resin (strongly crosslinked) consist of crosslinkable chain molecules. In contrast, thermoplastic resins are plastics in which the macromolecules consist of linear or branched chains and are only bound by intermolecular forces. Under the action of heat, the intermolecular forces weaken, which makes the thermoplastic resin deformable and processable. Temporary adhesives are one thermoplastic resin that usually softens above the glass transition temperature. Substrates bonded using a thermoplastic resin can often be separated from one another again by heating the thermoplastic resin above the glass transition temperature.

  These bonding adhesives include, among others, epoxy resins (thermal and / or UV crosslinking), photoresist materials, fluoropolymers, silsesquioxanes, benzocyclobutenes, polymethyl methacrylates, polydimethylsiloxanes, polyarylene ethers, Among the polyetheretherketones, liquid-crystalline polymers and thermoplastic copolymers such as polyvinylidene chloride.

  Temporary fixation is simple and fast to carry out, low cost, effective, reversible and physically and chemically stable. Most often, the carrier wafer is coated with a bonding adhesive and bonded to the product wafer in a bonding method. The adhesive layer may be applied over the entire surface of the carrier wafer and / or the product wafer. The temporary bond thus created withstands high temperatures and high forces. Furthermore, if necessary, further processing steps of the second side, for example the manufacture of bumps and / or bumps and / or other bonding layers and / or conductive paths and / or attachment of chips are carried out. It is also conceivable to replace the processing side of the product substrate by temporarily bonding the second carrier wafer on the exposed side and subsequently removing the first carrier wafer.

  Curing of the adhesive layer takes place, depending on the material, by electromagnetic radiation, preferably by UV light or IR light. The electromagnetic radiation has a wavelength in the range of 10 nm to 2000 nm, preferably 10 nm to 1500 nm, more preferably 10 nm to 1000 nm, most preferably 10 nm to 500 nm, most preferably 10 nm to 400 nm.

  Thermal curing is also conceivable. Thermal curing is performed at 0 ° C to 500 ° C, preferably 0 ° C to 400 ° C, more preferably 0 ° C to 300 ° C, and most preferably 0 ° C to 200 ° C.

  More generally, curing can be carried out by means of electromagnetic radiation, thermally, by means of electrical current, by means of magnetic fields or by other methods. Curing is preferably in the case of the present invention based on the polymerization of the basic material. In this case, the polymerization is initiated by so-called initiators. If electromagnetic radiation is used for curing, at least one of the two substrates, in particular the carrier wafer, is transparent to electromagnetic radiation in the wavelength range which causes crosslinking of the bonding adhesive. Thus, in particular the carrier wafer is a glass wafer or a sapphire wafer.

The adhesive layer has sufficient adhesion properties (non-peelable bonds) up to a predetermined temperature range in order to fix both substrates sufficiently. The adhesion properties are explained by the physical size of the adhesion. This adhesion is preferably defined by the energy per unit area required to separate the two surfaces bonded to one another. In this case, the energy is represented by J / m ² . A typical, empirically measured average value of energy per unit area between pure silicon and polymer is about 1.2 J / m ² . The corresponding values may vary depending on the coating material, the substrate material and the impurities, in this case the polymer. In the future, even more efficient coating materials are conceivable. The energy per unit area, in this case, 0.00001J / m ^2, preferably more than 0.0001J / m ^2, more preferably above 0.001J / m ^2, most preferably above 0.01 J / m ^2, greater than even most preferably 0.1 J / m ^2, greater than the upper most preferably the a 1 J / m ² greater.

  For separation, for example, both substrates are heated above this temperature range, so that the adhesive loses its adhesive properties and with the introduction of horizontal and / or vertical forces the carrier wafers of both wafers The product wafer is separated. At high temperatures, thermal decomposition of the polymer generally occurs. When using a thermoplastic resin, it is sufficient to heat to a temperature above the glass transition temperature.

  In addition, the edge area may be treated physically and / or chemically and / or thermomechanically and / or mechanically in order for the temporary bond to lose its adhesion.

  The adhesive layer can also be applied only to the edge of the product wafer and / or the carrier wafer. The inner region does not necessarily have to include an adhesive layer. The layers of the inner region may have any properties but are usually introduced as support material into the gaps of the individual structures, eg bumps.

  This separation procedure is similar to that of the overall bonding, but only the physical and / or chemical treatment of the edge area is necessary since the temporary bonding loses its adhesion. . Thus, with lower temperatures, shorter process times, lower material consumption of chemicals.

  In order to release the temporary bond again, the corresponding solvent is bonded through this hole, for example by means of a special laser and by the use of an additional separation layer or with a carrier wafer having holes with a slight diameter. There are innumerable other ways, such as by introducing all the way in. In addition, destruction or degradation of the edge area by laser, plasma etching, water or solvent injection may also be performed.

  The bonding adhesive can in particular be exposed through the glass substrate. A mask and / or a coated glass carrier is required to prevent uniform illumination. For this purpose, for example, the glass substrate is coated with a film having transparent areas and light opaque areas. This covering may be permanent or temporary. If the coating is temporary, the film can be removed again from the glass substrate. Thus, the glass carrier in the carrier substrate-product substrate-composite remains and can be utilized in further process steps as required. Alternatively, a mask is additionally used for the carrier substrate. In the case of the present invention, the mask may consist, inter alia, of a glass carrier in which there are opaque areas. The photosensitive bonding adhesive is exposed using UV light, in which case the areas to be cured are preset by the mask. The mask is used to not shield the area to be exposed.

  In particular, chucks, in particular spinner chucks, for example suction belts, perforations and / or suction cups, are suitable as storage devices for the storage of carrier substrate-product substrate-composites, in particular under negative pressure. Alternatively, electrostatic accommodation and / or mechanical accommodation, for example by means of lateral clamps, are also conceivable.

  In the case of another preferred embodiment of the invention, it is planned to use a multi-part shield instead of a mask to selectively expose selected areas of the laminate surface, in particular the edges. Be done.

  In the case of another embodiment of the invention, the light source for curing of the adhesive layer comprises a number of juxtaposed UV light sources, which are intended to be particularly controllable individually. The use of an array of UV light sources, which can be controlled individually, allows the UV light to selectively expose selected areas of the laminate surface, in particular the edges. Therefore, no mask is required in this embodiment.

  The post-processing debonding of the product substrate is firstly carried out in such a way as to chemically and / or mechanically peel off the cured, completely crosslinked bonding adhesive present at the edge. The radiation dose during curing has to be chosen such that the partially crosslinked areas can be separated again by slide-off or lift-off (with or without temperature).

  In the case of a preferred embodiment of the invention, it is envisaged that the debonding means comprise a liquid agent for the peeling of the bonding layer, in particular a solvent which selectively dissolves the bonding layer. The chemical dissolution of the bonding layer is particularly gentle to the substrate, and in particular if only the edge area of the substrate is provided with the bonding layer, so that the solvent can act rapidly from the side. This dissolution can take place very quickly during material selection. This approach can eliminate perforations in the carrier substrate and / or product substrate.

  In the case of a development of the invention, it is intended to heat the annular cross-linked part of the adhesive layer to a predetermined temperature, in particular for separating the product substrate and the carrier substrate. At this temperature, the adhesive, for example a thermoplastic resin, loses its adhesive properties so that it is possible to peel off the product substrate and the carrier substrate. In order not to impair the structure of the product substrate, it is preferable to consider that the heating be carried out only in the area of the annular, cross-linked (especially outer) adhesive layer. Suitable for heating the adhesive layer are, in particular, heating elements which have an annular heating part. Alternatively, local heating of the bonding layer can be effected by laser light, which may be advantageous in particular in the case of annular bonding layers.

  In the case of another embodiment of the invention, the decoupling means are intended to comprise mechanical separating means for peeling off the bonding layer, in particular blades for cutting the bonding layer. Thereby a particularly rapid separation of the product substrate from the carrier is possible. Combinations with mechanical separation means and liquid agents are also conceivable. An apparatus for separating the product substrate and the carrier substrate is described in the patent EP 2402981 B1. In EP 240 2 981 B1 (EP 240 2 981 B1) an apparatus and method for peeling a wafer from a carrier is described. The separation and separation device is carried out according to the patent EP 2402981 (EP 2402981 B1) and is not described in detail.

  In the ideal case, it is preferred that the carrier substrate and the product substrate be separable from one another, since the bonding adhesive is not particularly cross-linked in the central part. Otherwise, slide-off debonding must be performed. Document DE 10 2009 018 156 A1 (DE 102009018156 A1) describes bonding of the substrate with a substrate by means of a bonding layer, in which the separation of the substrate is achieved by sliding the substrate and the carrier substrate parallel to one another (slide-off) Describes an apparatus or method for separating a substrate from a carrier substrate. The document WO 2013/120648 (WO 2013/120648) describes a method of carrying out peeling by the introduction of a tensile force (lift-off).

  In general, a combination of chemical, thermal, mechanical and optical method steps is also possible for the detachment of the bonding layer.

  In the case of a further preferred embodiment, a material is used as the adhesive layer, which changes the state of the material at various wavelengths. Such light-controlled adhesive materials are described, for example, in the document US patent application publication 2015/0159058 (US 2015/0159058 Al), in which a liquid crystalline polymer is used. In this embodiment, the light controlled adhesive is preferably applied during rotation of the carrier substrate or product substrate and uniformly and uniformly distributed on the substrate by rotation of the substrate.

Alternatively, the light controlled adhesive is not applied to the entire surface between the carrier substrate and the product substrate, but only applied annularly to the edge area between the product substrate and the carrier substrate. After application, exposure to the appropriate wavelength (with or without a mask as needed) debonds in the form of a liquid adhesive. Adhesive wavelength lambda ₁ or wavelength region [Delta] [lambda] ₁ becomes solid. After processing of the back side of the substrate stack, exposure with the second wavelength λ ₂ or the second wavelength range Δλ ₂ will again render the adhesive liquid and can be debonded by slide off or lift off.

  The invention can be applied in combination with established industrial coating methods such as, for example, spin coating or spray coating. When using a suitable UV-controlled bonding adhesive for spatial curing, the manufacturing process is greatly simplified, since only the bonding layer needs to be applied to the entire surface. Thus, the coating of the substrate is quick, complete and standardized, which also brings the advantage of throughput. Furthermore, the substrate surface or the carrier substrate surface need not be pretreated, as no further coating (e.g. like an anti-adhesion layer or separation layer) is needed.

  The invention allows multiple uses of the carrier support without having to clean the carrier support in a laborious and expensive process. Only if the remainder of the bonding adhesive remains on the product substrate or carrier substrate upon peeling it can be removed by the cleaning step.

  Further advantages, features and details of the invention emerge from the following description of preferred embodiments and on the basis of the drawings.

FIG. 2 is a cross-sectional view of a product substrate with a structure. Sectional drawing of the product board | substrate after apply | coating a joining adhesive layer. Sectional drawing of the product board | substrate-carrier board | substrate-laminated body which has an exposure mask. The further sectional view of a product substrate-carrier substrate-layered product. FIG. 10 is a further cross-sectional view of a product substrate-carrier substrate-laminate after temporary bonding. FIG. 5 is a further cross-sectional view of a product substrate-carrier substrate-laminate and a UV source. FIG. 5 is a further cross-sectional view of a product substrate-carrier substrate-laminate and a UV light source array. FIG. 10 is a further cross-sectional view of a product substrate-carrier substrate-laminate with a bonding adhesive layer applied to the entire surface. FIG. 7 is a further cross-sectional view of a product substrate-carrier substrate-laminate with a bonding adhesive layer applied to a partial area.

  In these drawings, the same components or components having the same function are denoted by the same reference numerals.

  FIGS. 1 a-1 e show an exemplary inventive method procedure for temporarily bonding a product substrate 1 with a structure 2 and a carrier substrate 4. The method is carried out in a bonding chamber not shown in particular. The structure 2 may be, for example, a solder ball or chip and may form a topography (see FIG. 1a). It is also conceivable that the product substrate 1 has no topography because the structure 2 is not present or the structure 2 is not finished directly into the product substrate 1.

According to FIG. 1 b, the bonding adhesive layer 3 is applied over the entire surface of the structure 2 in and / or on the product substrate 1. The layer thickness of this coating is adapted to the topography and is in particular 1 μm to 15 mm, preferably 10 μm to 10 mm, more preferably 50 μm to 10 mm, most preferably 100 μm to 5 mm. A substrate container (not shown) allows for the handling of a substrate having a liquid layer on the substrate. This liquid layer is in particular a liquid thermoplastic resin which is present in the so-called boundary during contact with the carrier wafer. The solvent concentration of the liquid layer is especially 0 to 80%, preferably 0 to 65%, more preferably 0 to 50%. The layer thickness also depends, inter alia, on the viscosity of the solution. Viscosity is an extremely temperature-dependent physical property. The viscosity generally decreases as the temperature increases. The viscosity is 10 ⁶ Pa · s to 1 mPa · s at room temperature, preferably 10 ⁵ Pa · s to 1 Pa · s, more preferably 10 ⁴ mPa · s to ¹ Pa · s, most preferably 10 ³ Pa · s to 1 Pa・ S.

  After coating the product wafer 1 with the bonding adhesive 3 according to FIG. 1b, the product wafer is bonded to the carrier substrate 4 by alignment, contact and bonding in a temporary bonding method. Temporary bonding techniques are known to those skilled in the art.

  According to FIGS. 1c and 1d, the bonding adhesive layer 3 is exposed through the mask 5 to light, in particular UV light. The areas to be cured are preset by the mask 5. The mask 5 can have any shape, preferably circular, rectangular or square, more preferably a carrier substrate format, most preferably according to the standard format utilized in lithography. The diameter of the mask 5 preferably corresponds well to the diameter of the carrier substrate 4. The mask 5 then consists of areas 5a and 5b which are approximately equal to the size of the carrier substrate and which are transparent to the selected light wavelength range. Alternatively, a coated glass carrier may be used as a mask. The mask 5 shown in FIGS. 1 c and 1 d was manufactured such that the inner circular surface 5 b of the mask 5 is light impervious and the outer annular surface 5 a of the mask 5 is light transmissive. The outer annular surface 5 a has a ring width B. The exposure of the bonding adhesive layer 3 can take place from the side of the carrier substrate 4 and / or from the side of the product wafer 1. In particular, the transparency of the substrates / wafers which are respectively transparent for the electromagnetic radiation used is important.

  Alternatively, other materials are used as adhesives which, depending on the properties, are used as positive or negative adhesives and which require a correspondingly adapted exposure mask. Negative-acting adhesives polymerize upon exposure, but positive-acting adhesives become soluble or lose their adhesive properties in the corresponding solvent upon exposure.

  FIG. 1 d shows that the laminate 6 is exposed to UV light 7 through the mask 5. Through the mask 5, only the outer circular surface 5a is transparent to UV light. In this case, according to FIG. 1e, only the exposed outer area 8 of the layer 3 is crosslinked. The inner area 9 remains unexposed, so that no polymerization takes place in this area. The bonding layer 3 consists of two regions 8 and 9 which are cross-linked differently, in the case of this embodiment according to FIG. 1e, the polymerized outer annular region 8 being utilized for temporary bonding, and The inner circular area 9 which is not polymerized or only slightly polymerized is utilized for the embedding of the structure 2. The ring width B of the outer region 8 is 0 to 30 mm, preferably 0.1 to 20 mm, more preferably 0.25 to 10 mm, and most preferably 0.5 to 5 mm.

  Thus, the method according to the invention replaces the areas of high and low tackiness which had to be produced in the prior art by means of several process steps on the carrier wafer, with bonding layers. Thereby, no surface treatment of the substrate, for example a non-adhesive coating, is necessary. Debonding takes place in the annular area 8 between the carrier substrate and the product wafer.

  According to an exemplary embodiment of both FIGS. 2a and 2b, at least one UV light source 10, 10 'is used. In principle the omnidirectional radiation of the UV light source 10 (see FIG. 2a) is directed to the stack 6, for example by means of a reflector and / or a lens system (not shown). In this case, as uniform distribution of the radiation as possible to the stack 6 should be achieved. The UV light 7 used is optionally broadband light or specially adapted to the photoinitiator used in the bonding adhesive layer 3. The wavelength range of the UV curable material 3 is in particular 50 nm to 1000 nm, preferably 150 nm to 500 nm, more preferably 200 nm to 450 nm. The mask 5 defines the area 8 to be exposed.

In the case of another embodiment according to FIG. 2b, using an array of UV light sources 10 ', the UV light sources 10' are preferably individually controlled. The light source array 10 'may be guided directly to the substrate-carrier substrate-stack 6 or may use a light guide so that the light source 10' can be outside the bonding chamber. The bonding adhesive 3 is applied to the entire surface of the carrier 4 and / or the product wafer 1 in this embodiment. The carrier wafer and the product wafer are then bonded. One of the two wafers, in particular the carrier wafer 4, is transparent to electromagnetic radiation in the wavelength range which causes the bonding adhesive 3 to crosslink. By selective control of the UV light source 10 'from the array, only the partial area 8 where the bonding adhesive 3 is to be cured is exposed. This is preferably a peripheral area 8. The remaining part, in particular the central part 9, is not irradiated and is therefore not crosslinked. When a material whose state of matter changes at different wavelengths is used as the bonding adhesive 3, the bonding adhesive is again liquid by exposing it to the second wavelength λ ₂ or the second wavelength region Δλ ₂ after this processing. And debonding is possible.

  According to FIGS. 3a and 3b, the bonding adhesive layer can be applied to the entire surface 3 or to the partial area 3 '. If the bonding adhesive layer is applied to the partial area, the inner circular area 11 remains uncovered. Debonding (debonding) takes place in FIG. 3a within the annular area 8 between the carrier substrate and the product substrate. Similarly, in FIG. 3b, the debonding (debonding) takes place in the annular area 8 'between the carrier substrate and the product substrate. Here too, the area to be cured is preset by the mask 5. In this case, according to FIG. 3b, only the exposed outer area 8 'of the layer 3' is crosslinked. The inner area 9 'remains unexposed so that sufficient polymerization does not take place in this area. The bonding layer 3 'consists of two regions 8' and 9 'which are differently cross-linked in the case of this embodiment according to FIG. 3b, in which case the polymerized outer annular region 8' is temporarily bonded Used for

  In the embodiment described above, it is common that the bonding layer 3 consists of a heterogeneous layer after curing. This bonding layer 3 should be specially hardened at the edge. The remaining, in particular the central part, is not irradiated and is therefore not or only slightly crosslinked. Additional layers such as substrate surface treatment steps and separation layers are omitted. This results in a quicker and more simplified temporary bonding method. Thus, temporary fixation is simple, quick to carry out, low cost, effective, reversible and physically and chemically stable. Due to the fixing in the peripheral area, the bond between the carrier wafer and the product wafer can be peeled off simply and quickly chemically and / or mechanically after the production process.

  The application of the bonding adhesive 3 and the temporary bonding may be performed in vacuum and / or under an inert gas atmosphere to reduce defects. Conducting the working process under an inert gas atmosphere offers advantages such as better chemical durability, less defects and faster UV curing. Furthermore, under inert gas atmospheres, the resulting gas inclusions can be sufficiently avoided or eliminated. Alternatively, the entire work space can be blown with an inert gas and / or evacuated as an atmosphere defined by a vacuum device.

Reference Signs List 1 product substrate 2 structure 3,3 ′ bonding adhesive 4 carrier substrate 5 mask 5a transparent region 5b opaque region 6 laminated body 7 UV light 8,8 ′ outer region 9,9 ′ inner region 10,10 ′ UV light source 11 Uncovered area B Ring width

Claims (14)

Next steps:
a) applying a bonding adhesive (3,3 ') on the product substrate (1) and / or the carrier substrate (4) to form a bonding adhesive layer (3,3')
b) bonding the carrier substrate (4) to the product substrate (1) via the bonding adhesive layer (3,3 ');
c) curing only a partial area (8) of the bonding adhesive layer (3) and not curing or at least essentially curing the remaining areas (9, 9 ') of the bonding adhesive layer (3) A method of temporarily bonding a product substrate (1) with a carrier substrate (4), having no effect.   The method according to claim 1, wherein the bonding adhesive (3) is applied to the entire surface of the product substrate (1) and / or the carrier substrate (4).   The bonding adhesive (3 ') is applied to partial areas on the product substrate (1) and / or the carrier substrate (4), in particular the outer edge of the product substrate (1) and / or the carrier substrate (4) The method according to claim 1 or 2, wherein the part is applied in a ring form.   The method according to any of the preceding claims, wherein the bonding adhesive (3,3 ') is applied onto the structure (2) of the product substrate (1).   5. The method as claimed in claim 1, wherein the curing of the partial area (8, 8 ') is carried out by irradiation (7), in particular by UV irradiation (7).   A mask (5) is arranged between the radiation source (10) and the substrate (1, 4) in order to shield the remaining area (9, 9 ') from light. Method according to clause 1.   The curing of the partial regions (8, 8 ') is carried out by irradiating with a light source array with mutually arranged light sources, in particular UV light sources, the light sources being controllable in particular individually. The method according to any one of 1 to 6 above.   The method according to any of the preceding claims, wherein only the outermost edge area (8, 8 ') of the bonding adhesive layer (3, 3') is cured.   9. A method according to any one of the preceding claims, wherein the remaining area (9, 9 ') inside the bonding adhesive layer (3, 3') is not cured or at least essentially not cured. Method. a) coating means for applying a bonding adhesive (3,3 ') on the product substrate (1) and / or the carrier substrate (4) to form a bonding adhesive layer (3,3');
b) bonding means for bonding the carrier substrate (4) to the product substrate (1) via the bonding adhesive layer (3,3 ');
c) curing only the partial area (8, 8 ') of the bonding adhesive layer (3, 3') and curing the remaining area (9, 9 ') of the bonding adhesive layer (3, 3') Device for temporarily bonding a product substrate (1) with a carrier substrate (4), with a curing device (10, 10 ') which does not or at least essentially does not cure.   Device according to claim 10, wherein the curing device (10, 10 ') comprises a radiation source (10), in particular a UV light source (10).   The device according to claim 10 or 11, wherein a mask (5) is provided between the radiation source (10) and the substrate (1, 4) for shielding the remaining area (9, 9 ').   13. A device according to any of claims 10 to 12, wherein the mask (5) comprises a region (5a) transparent to the radiation of the radiation source (10) and a region (5b) impermeable to radiation. Device.   14. The device according to claim 10, wherein the curing device (10, 10 ') comprises a light source array (10') with in particular mutually controllable, independently controllable light sources.

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